1. Field of the Invention
The present invention relates to an electric steering control device for controlling an electric motor in a vehicle steering system.
2. Discussion of the Related Art
In an electric steering control device known heretofore of this kind, an electric current command value depending on the vehicle driving state is generated in a command value generating section, and a drive current corresponding to the electric current command value is applied from a motor drive circuit to an electric motor thereby to supply a required torque to a steering mechanism. The motor drive circuit is of the construction that various electronic elements (e.g., FET: Field Effect Transistors) are operated in dependence on the current command value thereby to output the corresponding drive current, as described in Japanese unexamined, published patent application No. 2001-253357.
By the way, the aforementioned electronic elements provided in the motor drive circuit vary in their characteristics in dependence on the temperature thereof. Thus, the output characteristic of the motor drive circuit varies upon the heat generation of the electronic elements and changes in the ambient temperatur. However, the aforementioned electric steering control device in the prior art takes such a configuration as to determine the electric current command value independently of the temperature of the motor drive circuit, and therefore, it is liable to occur that the steering feeling is varied in dependence on the ambient temperature and the heat generation of the motor drive circuit itself.